The International                        UPDATED 30th November 2011
Journal of Ventilation
Published Quarterly www.ijovent.org.uk          Subscribe to Journal  Online 

December 2011 Edition of the IJV now Published  Call for Papers

IJV now included in the Science Citation Index

Paper 7

Experimental Study of Turbulent Structures in a Non Isothermal Horizontal Jet Issuing from a Round Nozzle Distanced from a Wall

Frédéric Kuznik, Gilles Rusaouen and Jean Brau

CETHIL, CNRS, UMR 5008,
Bât. Sadi Carnot, 9 rue de la Physique, FR-69621, Villeurbanne
INSA-Lyon, Université de Lyon

Abstract

A non isothermal horizontal jet issuing from a round nozzle distanced from a wall is investigated experimentally. We consider four cases: an isothermal jet, a hot air jet, a cold air jet interacting with the wall and a cold air jet falling down without reaching the wall. The jet expansion rates show two categories. These are (1) an isothermal jet and cold jet not adhering to the wall, with a vertical expansion rate higher than the lateral rate and (2) a non isothermal jet adhering to the wall, with a lateral expansion rate higher than the vertical one. The turbulence structure analysis confirms two categories: the first is a highly anisotropic structure which is mainly cigar axisymmetric and the second one is subject to instabilities linked to lateral air ejections. This is confirmed by a spectral analysis of the turbulent component of the flow. A scenario of coherent structures evolution is proposed.

Key words:  wall jet, buoyancy force, Lumley triangle, turbulence anisotropy, coherent structures, spectral analysis.

Contents

Paper 1
System Design for Demand Controlled Ventilation in Multi-Family Dwellings

Paper 2
A Long-Term Modelling Study of Ventilation and VOC Distribution in Multi-family Residential Buildings in the Severe Cold Region of China

Paper 3
Evaluating the Influence of Window Types on the Natural Ventilation Performance of Residential Buildings in Hong Kong

Paper 4
Effects of Urban Ventilation Patterns on the Carbon Monoxide Concentration in a High-Rise Mega City

Paper 5
A Measurement Study on the Indoor Climate of a College Classroom

Paper 6
Natural Personalised Ventilation - A Novel Approach

Paper 7
Experimental Study of Turbulent Structures in a Non Isothermal Horizontal Jet Issuing from a Round Nozzle Distanced from a Wall

Paper 8
Case Study Assessment of Local and General Thermal Comfort by Means of Local Skin Temperature

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